The present invention relates to machines for mounting resiliently latching lids on containers, and particularly to a machine for placing circular lids including pouring spouts on such containers in a desired orientation.
Bucket-like containers, usually molded of sturdy plastic material, are widely used to contain powdered or liquid products. A lid is placed on each container, where it is pressed downward into place and thereafter held securely by a latching interaction between the rim of the container and the resilient depending and surrounding rim of the lid. Products may be placed in such containers before application of a lid, or through a pouring spout defined in the lid, after the lid has been attached to the container.
Well-known machinery has previously been available to place lids in position atop such containers as each container moves along on a conveyor. Some difficulty has been encountered in thereafter pressing a lid downward into latching engagement on an empty container. In such previously available machinery freely rotatable rollers located above the conveyor have been used to force the lid downward into its latching position atop a container. The rollers of such previous machinery, however, have often overturned empty containers as the lid encounters the first of the rollers and the bottom of the container continues to be carried along by the conveyor.
Previously available machines dispense lids from a vertical stack into position for being fastened atop a container. Thus, the entire weight of the stack of lids has had to be supported by the dispensing mechanism. This places too much stress on the dispensing mechanism, with the result that dependability of the dispensing mechanism is less than desired, and with the further result that the height of the stack causes undesirable variations in the operation of the dispensing mechanism. Because the weight of a stack of lids is a limiting factor for such machinery, it has previously been necessary to provide lids frequently to replenish the small stack.
When a lid for a container includes a pouring spout, and the container has a bail or handle, the pouring spout portion of the lid must be located properly with respect to the bail or handle in order to make it useful for supporting the container while the contents are poured. Previously it has been necessary to place lids in the correct orientation manually in a stack of lids to be applied to containers by machine. It would be preferable to have the lids automatically oriented properly for application to the upwardly-open containers.
What is needed, therefore, is an improved method for installing lids on upwardly open containers, and a lid installing machine capable of accepting and installing more than a few lids without having to be resupplied with lids, and without causing harmful stress on the machinery dispensing the lids individually to be placed on containers. Such an improved machine should also provide for reliable application of lids without overturning empty containers, and should also have the ability to orient lids automatically to correspond with the location of the bail of a container to which a lid is being applied.